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Version: 5.2 (upcoming)


'a' or 'an' before H?

  • Use 'an' before a silent H: an heir, an hour
  • Use 'a' before an aspirated H: a hero, a hotel, a historian
  • With abbreviations, be guided by pronunciation: eg an HTML document

Abbreviations and acronyms

  • The first time you use an abbreviation or acronym explain it in full on each page then refer to it by initials unless it's well known, eg HTML, CSS etc.
  • If you think your acronym is well known, please provide evidence that 80% of the UK population will understand, and commonly use, the term. Evidence can be from search analytics or testing of a representative sample.
  • Don't use full stops in abbreviations – BBC, not B.B.C.
  • Use all capitals if an abbreviation is pronounced as the individual letters (an initialism): HTML, CSS
  • If it is an acronym (pronounced as a word) spell out with initial capital, eg Nasa, Nato, Unicef, unless it can be considered to have entered the language as an everyday word, such as laser and sim card.
  • Note that pdf is lowercase.


  • Use on French, German, Portuguese, Spanish and Irish Gaelic words (but not anglicised French words such as cafe, apart from exposé, lamé, résumé, roué).


  • Don't use Americanisms. You 'fill in' a form, not 'fill out' a form.
  • Exceptions include where it's part of a specific name, eg '4th Mechanized Brigade'.
  • Use the 'ise' rather than 'ize' suffix, eg organise not organize (this isn't actually an Americanism but is often seen as such).


See numbers


See select.

Colour codes

Hex colours are case insensitive so it doesnt matter if we use upper or lowercase. However we should be consistent in our usage. As the color selector fields uses lowercase then the text should also user lowercase for consistency.


Use contractions sparingly eg can't. Avoid using you'll, you've, should've, could've, would've etc – these are hard to read.


  • use upper case for months eg January, February
  • don't use a comma between the month and year, eg 14 June 2012
  • when space is an issue, eg tables, publication titles etc, you can use truncated months, eg Jan, Feb, Mar
  • use 'to' in date ranges – not hyphens, en rules or em dashes. For example: copyright year 2011 to 2012
  • Monday to Friday, 9am to 5pm (put different days on a new line, don't separate with a comma etc)
  • 10 November to 21 December
  • don't use 'quarter' for dates; use the months, for example: 'expenses, Jan to Mar 2013'
  • when referring to 'today' (eg in a news article) make sure you include the date as well eg 'The minister announced today (14 June 2012) that…'

Email and Email Address

Email should refer to the item that you send Email address should be used if referring to their actual address


  • Enter an email address for the user.
  • Select which mailer for the delivery of site email.

File Size display:

  • If less than 1 KB, display <1 KB
  • 1 KB to 1,023 KB, display 357 KB
  • 1 MB to 1,047 MB, display 2.5MB (only one decimal place)
  • 1 GB+, display 3.8 GB (only one decimal place)

Geography and regions

  • Use lower case for north, south, east and west, except when they're part of a name or recognised region. So, 'the south-west' (compass direction), but 'the South West' (administrative region).
  • Use lower case for: the north, the south of England, the south-west, north-east Scotland, south Wales, the west, western Europe, the far east, south-east Asia.
  • Use upper case for: East End, West End (London), Middle East, Central America, South America, Latin America.


  • Use a minus sign for negative numbers with no space: –6
  • Ratios have no space either side of the colon: 5:12
  • One space each side of symbols: +, –, ×, ÷ and = (eg 2 + 2 = 4)
  • Use the minus sign for subtraction not the dash.
  • Use the correct symbol for the multiplication sign (×), not the letter x. (× or ×)


  • Use lower case for all measurements eg px, em, w and h
  • Use the metric system for mass and non-web measurements eg kg, cm and m
  • Use celsius for temperature eg 34c
  • For all other measurements use SI


  • Use the £ symbol with no space: – £75.
  • Don't use decimals unless pence are included, for example use: £75.50 but not £75.00.
  • Don't use '£0.xx million' for amounts less than £1 million.
  • Write out 'pence' in full eg 'calls will cost 4 pence per minute from a landline'.
  • Currencies are lowercase.

Multi-factor Authentication

Always use the hyphenated word. Multi-factor must always be a single hyphenated word and only the complete words should be capitalised.


(I have changed this based on the NNG findings (

  • Write numbers with digits, not letters (23, not twenty-three).
  • Use numerals even when the number is the first word in a sentence or bullet point.
  • Use numerals for big numbers up to one billion. As a compromise, you can often use numerals for the significant digits and write out the magnitude as a word. For example, write 24 billion.
  • "Enter the number of hits to increase the counter by."
  • "Limit the amount of text to display"


Try to avoid using them as they are not global. spring, summer, autumn, winter are lowercase.


Select a check box item not check a check box item.

Sentence length

Don't use long sentences – check any sentences with more than 25 words to see if you can split them to make them clearer.

Singular and Plural

In general a string with a constant of ARTICLE_PUBLISHED_1 should have a value of "Article published." and not "1 Article ...


  • use 'to' in time ranges – not hyphens, en rules or em dashes, eg 10am to 11am (not 10–11am)
  • 5:30pm (not 1730hrs)
  • midnight, not 00:00
  • midday, not 12 noon, noon or 12pm


Titles should:

  • be no longer than 65 characters
  • be unique, clear and descriptive
  • be front-loaded and optimised for search
  • use a colon to break up longer titles
  • not have a full stop at the end
  • not use acronyms unless they are well-known eg HTML


Tooltips should:

  • be as short as possible
  • end with a full stop
  • not repeat the title or body text
  • be clear and specific

Trademarked Name

This should always be written with a capital letter unless the trademark is for lowercase eg iPhone.

Two Factor Authentication

This should not be used. See Multi-factor Authentication.